EDIT: These days, please harvest amplifier chips from active computer speakers instead. They are plentiful and contain only what you need in a nice package.
For a project of mine, I needed a stereo amplifier. I had some old Sound Blaster ISA cards (and later got more, which are also now listed here), with different amplifiers:
|card name||model number||year||amplifier IC||Power output|
|Sound Blaster 16||CT2290||1994||TEA2025B||2 x 2.4 W|
|Sound Blaster 16 Value||CT2779||1994||TEA2025B||2 x 2.4 W|
|Sound Blaster 16||CT2940||1995||TDA1517P||2 x 6 W|
|Sound Blaster||CT4170||1997||TDA1517P||2 x 6 W|
|Sound Blaster Vibra 16||CT4180||1997||TDA1517P||2 x 6 W|
I liked TDA1517P, because it had so few additional components.
Seems to work fine!